(a) Field of the Invention
The present invention relates to a thin film transistor display panel and a manufacturing method thereof, and more particularly, to a thin film transistor display panel for a liquid crystal display including an oxide semiconductor layer and a manufacturing method thereof.
(b) Description of the Related Art
A liquid crystal display typically uses an electric field to adjust the light transmittance through a liquid crystal, thereby displaying images. To this end, the liquid crystal display includes a liquid crystal panel in which pixels are arranged in a matrix, and a drive circuit for driving the liquid crystal panel.
The liquid crystal panel includes a thin film transistor (hereinafter, referred to as ‘TFT’) display panel and a color filter panel that face each other, spacers disposed between the TFT display and color filter panels for maintaining a predetermined cell gap between the two panels, and a liquid crystal layer filling the cell gap.
In general, the TFT display panel includes an array of TFTs and further includes a passivation film for protecting the TFTs, and pixel electrodes electrically connected to the TFTs. In this case, in order to electrically connect the TFTs and the pixel electrodes, contact holes are formed in the passivation film, and such contact holes are generally formed in the passivation film by etching using an etch agent.
However, when the vertical structure of the passivation film with etched openings is unstable, problems may occur in the electrical connection between the TFTs and the pixel electrodes, resulting in errors in the operations of the pixels.
TFTs used in liquid crystal displays are typically classified into amorphous silicon TFTs and polycrystalline silicon TFTs on the basis of the materials constituting channel regions of switching elements. Amorphous silicon TFTs have a low charge mobility, for example, about 0.5 cm2/Vs, but make it possible to realize uniform electric characteristics with respect to a large-area display. In contrast, polycrystalline silicon TFTs have a high charge mobility, for example, several hundred cm2/Vs, but make it difficult to realize uniform electric characteristics with respect to a large-area display.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.